1. Field of the Invention
The present invention relates to a method for topdressing an activity field, with essentially solid elastomeric particles, particularly crumb rubber, to reduce abrasion of turfgrass. In particular, the present invention relates to a method wherein the particles produce enhanced greening and health of the turfgrass on an athletic field or playground.
2. Description of Related Art
Topdressing plays many roles in enhancing the turfgrass environment. Among these benefits, include thatch control, smooth surface, modification of the surface soil and winter protection (Beard, J. B., Turfgrass Science and Culture, p. 494, (1973)). Putting greens and sports fields profit from this maintenance practice, primarily because they are high traffic areas and because of the importance of a smooth and uniform surface. In particular, soccer and football fields are subject to more abrasive action due to the nature of the games played on them. A topdressing of a sand/organic matter mix or all sand is used to promote qualities previously mentioned. However, the most intensively worn out areas, usually by mid-season, are past the point of repair, and topdressing does not alleviate the problem. Additionally, sand has abrasive edges, leading to scarification of the crown tissue area or portion of the root. This is detrimental for the playing field due to intense traffic areas on the field becoming the most sparse areas (least dense) of the turf stand. Soccer and football fields show the most wear in between the hashmarks and the goal mouth and in mid-field portions. Further, the abrasive action of the sand is detrimental to turf in areas that are under reduced light conditions (i.e. shade), such as in enclosed stadiums with natural turf, and subsequently reduced growing and recuperative conditions. This effect is magnified especially on low to medium maintenance sports fields. With the absence of turf on the field, the playing quality and aesthetics are dramatically reduced and this ultimately leads to player injuries. Other fields (areas) including horseracing tracks, walk paths, golf course cart paths suffer from abrasive use.
The patent art has shown the amendment of soil with rubber particles, so that the root is below the amendment. U.S. Pat. No. 5,014,462 to Malmgren et al. The rubber particles comprise between 10% to 40% by volume of the amendment with the balance being sand and peat. The problem with this method is that the sand still abrades the root of the turfgrass during use of the turf as a field. Even as much as 80% by volume of rubber to sand produces the same result. Further, the crown of the turfgrass which is at the ground level are not protected by this method, U.K. 2196539A to Heerkens shows a similar method.
U.S. Pat. No. 3,067,542 to O'Brien describes the use of a granular polyurethane foam as a topdressing for soil. The patent is not concerned with turfgrass. The granules in this case are open celled and are too easily dislodged and are not sufficiently rigid to prevent abrasions. U.S. Pat. No. 3,299,567 to Perkins describes the use of fiber glass strands as a topdressing. These are too brittle and can have very sharp edges which damage the root of turfgrass.
U.S. Pat. No. 4,900,010 to Wengmann et al describes the use of a mixture of bark and fibers as a topdressing. The bark is rapidly degraded by use and by decomposition. U.S. Pat. No. 4,166,340 to Pluenneke describes the use of rubber particles on the bottom of a pot for a plant. This does nothing to protect the crown of the plant.